Micro-computed tomography (mu CT) is a rapidly emerging technology for nondestructive, three-dimensional imaging of tissues, organs and whole organisms. This aim of this proposal is to acquire funds to purchase a high-resolution desktop mu CT system (mu CT40, Scanco Medical AG, Basserdorf, Switzerland) to be shared among 10 investigators funded by 8 NIH grants. The research projects that will use this instrumentation address skeletal, urologic, respiratory and metastatic diseases. Currently, these projects use multiple methods including standard radiography, magnetic resonance imaging, ultrasound, histomorphometry, molecular assays, mechanical testing and finite element analysis to assess organ and tissue structure, tissue healing and tissue mechanical properties. Micro-computed tomography adds an important dimension to this existing armamentarium by providing capabilities for detailed and quantitative 3-D characterization. Measurements such as bone mineral density, trabecular thickness, vascular connectivity, and alveolar cluster size distribution derived from mu CT scans are critical in elucidating relationships between structure and function in both healthy and diseased tissues. The nondestructive nature of mu CT imaging allows subsequent analysis of a single specimen by any number of complimentary techniques, including histology and mechanical testing; thus, use of mu CT does not require an increase in specimen or animal numbers. Our previous use of mu CT has been limited by access to this instrumentation, rather than the utility of this technology for our research. Indeed, mu CT is an essential technology for several ongoing projects which address age-related bone fragility and shock wave-induced fracture of kidney stones. The high-resolution desktop mu CT system requested in this application will be fully utilized by a team of investigators who have strong track record of providing important results, as well new research directions, in skeletal healing, osteoporosis, osteoarthritis, shock wave lithotripsy, emphysema and lymphoma.